Probleme de bouton select des cle secondaire

<?php

$req = "select * from mat ";
	$requete= $connexion->prepare($req);
	$requete->execute();
$req2 = "select * from mat ";
	$requete2= $connexion->prepare($req2);
	$requete2->execute();
$req3 = "select * from mat ";
	$requete3= $connexion->prepare($req3);
	$requete3->execute();
$req1 = "select * from user ";
	$requete1= $connexion->prepare($req1);
	$requete1->execute();

?>
	
	
	
<h2><center>Enregistrement de nouveau historique</center></h2>

<form class='formulaire' action="index.php?page=modules/historique/create.php" method= "post"> <br/>
	Numero historique :
	<input name="numhist" type ="text"/>
	<br/> <br/>
	Date historique :
	<input name="datehist" type ="text"/>
	<br/> <br/>
	Numero materiel :
	<select name="numserieaff">
		
		<?php 
			while($mat=$requete->fetch(PDO::FETCH_OBJ)){
			?>

			<option value="<?php echo $mat->numserieaff?>" >
			<?php echo $mat->numserieaff ?>
			
			</option>
			<?php } ?>
		</select><br/>
		<br/><br/>
		Caracteristique :
	<select name="caractmataff">
		
		<?php 
			while($mat=$requete2->fetch(PDO::FETCH_OBJ)){
			?>

			<option value="<?php echo $mat->caractmataff?>" >
			<?php echo $mat->caractmataff ?>
			
			</option>
			<?php } ?>
		</select><br/>
		<br/><br/>
		Date Installation  :
	<select name="dateinsaff">
		
		<?php 
			while($mat=$requete3->fetch(PDO::FETCH_OBJ)){
			?>

			<option value="<?php echo $mat->dateinsaff?>" >
			<?php echo $mat->dateinsaff ?>
			
			</option>
			<?php } ?>
		</select><br/>
		<br/><br/>
	Numero utilisateur  :
		<select name="nomuser">
		
		<?php 
			while($user=$requete1->fetch(PDO::FETCH_OBJ)){
			?>

			<option value="<?php echo $user->nomuser?>" >
			<?php echo $user->nomuser ?>
			
			</option>
			<?php } ?>
		</select><br/>
 <br/></br>
<input id ="annuler" name="annuler" type="reset" value="Annuler"/>
<input id ="annuler" name="valider" type="submit" value="Valider"/>
 <br/></br>
</form>